What is this?!!?

[dukexc]

I picked up some live rock from a really established tank. The rock was in teh sump. This red thing is growing on it. What is it? Also...The rock had sponges, the definitely died as soon as they were exposed to air...how do i deal with them so they don't spike my levels. Thanks, Bryanhttp://reefcentral.com/gallery/data/500/30453ufo.jpg

[mejiggery]

its a tunicate or sea squirt
http://discover.npr.org/features/feature.jhtml?wfId=875863

[rshimek]

Hi,

It is definitely a sea squirt or tunicate. See here (http://web.archive.org/web/20020804154459/www.animalnetwork.com/fish2/aqfm/1997/sep/wb/default.asp) for more information about them. These larger squirts are difficult to maintain, as they require a large amount of small planktonic food.

Good luck! :D